Nobel Prize Undercuts Evolutionary Genetics
As the cell becomes
more complicated,
evolution becomes
less probable
by Jerry Bergman, PhD
— The discovery of microRNAs adds another nail in the Darwinian coffin —
In Darwin’s day, the cell was viewed as a simple bag of protein and water. Darwin knew it had a membrane, nucleus, and nucleolus because these structures were visible in the light microscopes of his time. He had no understanding of specifically what these organelles did in the cell, nor was he aware of the thousands of other structures in eukaryotic cells that are required for the cell to function properly.
In Darwin’s day, a cell was
but a microscopic lump of jelly-like substance, or protoplasm… This protoplasm, although entirely destitute of texture, and consequently destitute of organs, is nevertheless considered to be an Organism.[1]
This common view of the cell in the 19th century came not from studying mammal cells, but rather from researching complex, single-celled organisms including monads, vibriones, protamoebae, and polythalamia. Mammal cells in the 1860s were understood as consisting of “a nucleus with surrounding protoplasm [with] no trace of organization.”[2]
The discovery of microRNA in the late 1980s adds to our modern understanding of the cell. It is now, in fact, recognized as the most complex microstructure in the universe.
A single human cell, like a skin cell, or liver cell, is far more complex than the space shuttle. Or than a nuclear submarine. Even more astounding is the fact that the billions of biochemical molecules inside cells act like incredibly intelligent beings, with eyes, swim fins, and a brain. They know just where to go, just what to do, and just when to do it. And they do their thing in incredibly fast motion… The system that synthesizes proteins is unbelievably complex, yet two thousand protein molecules are synthesized every second in every cell in your body, 24/7. If you could enlarge a cell to the size of a basketball, and if you could open it up and watch, you would see a constant and endless blur of activity.[3]
Illustration of some the basic parts of the cell. Click for source.
Today, as a result of the discovery of microRNAs, the cell has become significantly more complex than the above description. A medical researcher with a PhD in Complex Systems & Solid State Physics from Charles University in Prague marveled at the cell in these words:
Living cells are profoundly complex. The number of working parts of a single living cell that is constituting its function is comparable to the number of living people on the Earth at this very moment. Number of involved atoms is much higher! Can anyone imagine the complexity of the relationships among all living people at the personal, social, ethnic, and national levels? In a living cell it is similar…. Each part of it interacts with some other parts, some parts make functional clusters. Additionally, there are operating high-level emergent structures that are not encoded in the low-level operational units.[4]
The discovery of microRNAs adds yet one more level of complexity to the previous understanding of cellular complexity.
The History of Its Discovery
‘Oh, my god,’ we missed this whole layer of gene regulation completely.”
In the 1990s, Victor Ambros and Gary Ruvkun identified genes that encoded a microRNA in the roundworm, Caenorhabditis elegans., which they named lin4. For years, the discovery was viewed as a design unique to roundworms, with no relevance to other organisms. The discovery that microRNAs are conserved [meaning they have a similar design and have very similar functions] across the tree of life caused the field to explode. This discovery, observed RNA biologist Eric Miska, was “a watershed moment where everybody realized ‘Oh, my god,’ we missed this whole layer of gene regulation completely.”[5]
MicroRNAs are now recognized as critical to the functioning of the cell, and thus to life. Their discovery was so important that the 2024 Nobel prize in Physiology or Medicine was awarded to geneticists Victor Ambros and Gary Ruvkun this year (October 2024).[6] The Nobel prize is, by far, the most prestigious honor in science. The importance of the discovery, as explained by Anne Mirabella, added significantly to our knowledge of the cell. She compares a cell to a quality watch—an illustration used by William Paley to prove the existence of an intelligent creator:
There is nothing more precise than a Swiss watch — besides the pattern of development of the nematode worm Caenorhabditis elegans, one of the most studied and useful animal models. The postembryonic development of C. elegans entails passage through four accurately coordinated larval stages (L1–L4) interspersed with molts. In the mid‑1980s, many scientists were interested in genetic aberrations that could alter the precise timing of C. elegans development. Genes that, when manipulated, could delay or advance the nematode’s cell cycle and developmental-stage progression were called heterochronic genes.[7]
Cytologists now know that
Down-regulation of the protein LIN‑14 was crucial for the progression from the first larval stage (L1) to the second larval stage (L2). Loss‑of‑function mutations in lin‑14 cause C. elegans to skip a beat, starting development from L2. On the other hand, mutations in another gene, lin‑4, halted developmental progression indefinitely at the L1 stage. Surprisingly, lin‑4 did not encode a protein; instead, it is transcribed into a small non-coding RNA with sequence complementarity to the 3ʹ untranslated region (3ʹ UTR) of lin‑14.[8]
This small non-coding RNA was determined to be a microRNA, the first one to be discovered.
As explained by Ashish Bihani, a Ph.D. Student at Centre for Cellular and Molecular Biology, scientists have a lot to learn about the cell:
1. Along with serving as a template for translation, some types of RNA also help in producing cellular machinery even has enzymatic properties.
2. Out of about a million proteins in the human proteome, barely 10,000 have experimentally determined structures. People are trying to extrapolate those by comparing sequences of proteins in phylogenetic proximity. We are still in the dark about many feedback systems, post-translational modifications, and signaling cascades.
2. The eukaryotic cell membrane consists of a lipid bilayer containing many proton pumps, ion channels, and porins made up of complex proteins that are part of several signaling pathways. The transport across the membrane (which is dictated by the endocrine/neural system) is tightly controlled. The details are still unknown
4. The cell structure and position is maintained by microtubules and adhesion junctions which carry proteins and signaling molecules. Again, a lot of this we in the dark about.
5. Scientists that make significant contribution to science spend their life researching two or three proteins or one particular pathway. And still the field of cell signaling has so much yet to discover.[9]
Each of the 14 major organelles also manifest enormous complexity as shown in this example. From Wikimedia Commons.
Summary
Since I have begun my career studying and teaching cell biology, our knowledge of the cell has increased enormously. Each new discovery, including, of DNA, RNA, RNAi, mRNA, siRNA, DNA polymerase, restriction enzymes, reverse transcriptase, and now microRNA, has both increased our knowledge of the cell as well as our understanding of its complexity.[10] Mutations discovered in microRNA research have constantly resulted in loss of information, not a gain of information. Conversely, mutations have helped researchers better understand the functions of the genomes and proteins used in the cell. As our knowledge of the cell’s complexity increases, the probability of its evolution being caused by mutations and natural selection drastically decreases.
References
[1] Lewes, G.H., “Mr. Darwin’s hypotheses,” Fortnightly Review, Volume 16, p. 61, 1 April 1868.
[2] Lewes, 1868, p. 61.
[3] Blume, S., https://www.quora.com/How-complex-is-a-cell-compared-to-the-most-complex-human-design.
[4] Kroc, J., “Living cells are profoundly complex.” https://www.quora.com/How-complex-is-a-cell-compared-to-the-most-complex-human-design.
[5] Callaway, E. and K.Sanderson, “Medicine Nobel awarded for gene-regulating ‘microRNAs’,” Nature News, https://www.nature.com/articles/d41586-024-03212-9, 7 October 2024.
[6] Callaway and Sanderson, 2024.
[7] Mirabella, A., “MicroRNAs emerge as potent post-transcriptional gene regulators,” Nature, https://www.nature.com/articles/d42859-019-00078-0, 2019; emphasis added.
[8] Mirabella, 2019; emphasis added.
[9] Bihani, A. How can simple cells make up a complex human body? https://www.quora.com/profile/Ashish-Bihani.
[10] Tomkins, J. The Design and Complexity of the Cell. Dallas, TX: Institution of Creation Research, 2012.
For more on the impact of the Nobel Prize discovery of microRNAs, see Evolution News 10 Oct 2024.
Dr. Jerry Bergman has taught biology, genetics, chemistry, biochemistry, anthropology, geology, and microbiology for over 40 years at several colleges and universities including Bowling Green State University, Medical College of Ohio where he was a research associate in experimental pathology, and The University of Toledo. He is a graduate of the Medical College of Ohio, Wayne State University in Detroit, the University of Toledo, and Bowling Green State University. He has over 1,900 publications in 14 languages and 40 books and monographs. His books and textbooks that include chapters that he authored are in over 1,800 college libraries in 27 countries. So far over 80,000 copies of the 60 books and monographs that he has authored or co-authored are in print. For more articles by Dr Bergman, see his Author Profile.